Ultrastructural Changes in the Circumventricular Organs After Experimental Traumatic Brain Injury
Objectives: Trauma and bleeding can affect the functions of circumventricular organs (CVOs), which are essential for most autonomic and endocrine functions. The aim of this study was to investigate the ultrastructural changes at circumventricular organs after traumatic brain injury.
Methods: Two experimental groups were used: Traumatic injury group and a control group, six Wistar albino rats each. Under general anaesthesia, a lead object weighing 450 g was allowed to fall freely from a height of 90 cm through a copper tube onto the metal discover the skulls of the rats. 48 hours after trauma and control animals were anaesthetized. Rats were perfused with a fixation fluid (3 % paraformaldehyde and 1 % gluteraldehyde in PBS) until the heart stopped. Tissues containing SFO, OVLT, ME, AP were obtained using Paxinos & Watson Rat Stereotaxic Atlas. Ultrastructure examinations were done using TEM.
Results: In all traumatic animals, edematous areas were abundant in neuropil. There were degeneration findings at neural and glial cell bodies, neuropil and myelinated nerve fibres. Degeneration at myelin sheath and degenerated organel remnants within the axoplasm were seen. There were disruption at myelinated and nonmyelinated axons. The number of the secretory granules at ME were reduced.
Discussion: Changes observed in CVOs 48 hours after experimental head injury has a potential role in explaining functional and endocrine dysfunctions seen after TBI.